To solve this problem, we need to identify which hormone promotes internode or petiole elongation in deep water rice. Let's analyze each option:$\newline \bullet$Option 1: $GA_3 \newline$ - Gibberellic acid (GA_3) is known to promote stem elongation and growth in many plants. However, in the specific case of deep water rice, it is not the primary hormone responsible for internode elongation.$\newline \bullet$Option 2: Kinetin$\newline$